Serdar Özgen

Cervical spondylotic myelopathy: surgical results and factors affecting prognosis.

OBJECTIVE A variety of factors may affect surgical outcome in patients with cervical spondylotic myelopathy. The aim of this study is to determine these factors on the basis of preoperative radiological and clinical data. METHODS To assess the factors affecting postoperative outcome after surgery for cervical spondylotic myelopathy, the clinical and radiological data of 27 patients with cervical spondylotic myelopathy were reviewed. Functional and neurological statuses were assessed using the Japanese Orthopaedic Association (JOA) scale modified by Benzel. In all patients, the effect of age, symptom duration, cervical curvature, presence or absence of preoperative high signal intensity within the spinal cord as revealed by T2-weighted magnetic resonance imaging, and diameters of the spinal canal and vertebral body on pre- and postoperative neurological statuses were investigated. Plain radiographs were obtained for all patients, magnetic resonance images for 21 patients (77.8%), computed tomographic scans for 13 patients (48.1%), myelograms for 6 patients (22.2%), and computed tomographic myelograms for 4 patients (14.8%). There were five patients with a JOA score of 10, six patients with a JOA score of 11, six patients with a JOA score of 12, four patients with a JOA score of 13, four patients with a JOA score of 14, one patient with a JOA score of 15, and one patient with a JOA score of 16. All patients underwent cervical laminectomies. The mean follow-up period was 54.1 months. The final neurological examinations revealed improvement in the JOA scores of 85.1 % of the patients. RESULTS Statistical analysis of all patients revealed mean JOA scores of 12.185 +/- 1.618 and 14.370 +/- 2.15 before surgery and at final examination, respectively. The difference between the preoperative JOA score and the final JOA score was determined to be statistically significant (P < 0.0001). Statistical analyses also showed better neurological improvement in patients younger than 60 years and in patients with normal preoperative cervical lordosis. Although patients without preoperative high signal intensity of the spinal cord showed a better improvement rate than did patients with preoperative high signal intensity, the determined difference was statistically insignificant. CONCLUSION It can be concluded that age and abnormal cervical curvature predict less postoperative neurological improvement. The presence of preoperative high signal intensity within the spinal cord may also reflect less neurological improvement.

Findings and outcome of revision lumbar disc surgery.

One hundred fourteen patients (64 men, 50 women) with prior lumbar disc surgery underwent a reexploration for intractable back and/or leg pain. The finding in revision surgery included disc herniation in 89 cases (78%), epidural fibrosis in 14 cases (12.2%), adhesive arachnoiditis in 4 cases (3.5%), isolated lateral spinal stenosis in 3 cases (2.6%), and iatrogenic instability in 4 cases (3.5%). Review of operative reports of patients who underwent a first operation in our institute revealed that seven cases (12.5%) had a second laminotomy without a discectomy in addition to the previous laminotomy and discectomy performed in the same session. Fifty-six of the patients with disc hemiation in revision surgery had a true recurrence. Disc hemiation was protruded in 38 cases (42.8%), extruded in 44 cases (49.4%), and sequestrated in 7 cases (7.8%). The outcome was assessed using Prolos functional and economic scale. According to Prolos scale, a good outcome was detected in 79 cases (69.2%), moderate in 22 (19.2%), and a poor outcome was detected in 13 cases (11.4%). The best outcome was achieved in patients with disc hemiation. It is concluded that recurrent disc disease is the most important cause of reexploration. This fact dictates a careful preoperative workup and discectomy in the first intervention. The likelihood of occurrence of disc herniation in the negative laminotomy level (i.e., laminotomy without discectomy procedure) also requires a careful preoperative radiologic workup before lumbar disc surgery.

A retrospective review of cervical corpectomy: indications, complications and outcome

Summary.Background. Cervical corpectomy is a common spinal surgery procedure used to decompress the spinal cord in numerous degenerative, traumatic and neoplastic conditions. The aim of this study was to investigate the indications, complications and outcomes in past cervical corpectomy cases at one centre.Method. 72 patients who underwent cervical corpectomy between February 1992 and June 2001 were retrospectively investigated.Findings. The indications for this operation were degenerative spondylitic disease (26 cases; 36.1%), trauma (18 cases; 25%), tumour (11 cases; 15.3%), infection (10 cases; 13.9%), and ossification of the posterior longitudinal ligament (7 cases; 9.7%). Thirty-seven patients (51.4%) underwent one-level corpectomy, and 35 (48.6%) underwent two-level corpectomy. Autografts were used in 13 cases (18.1%) and allografts were used in 59 cases (81.9%). Anterior plate-screw fixation was performed in all cases. There were 31 postoperative complications in 15 (20.8%) patients. Twelve of the complications were surgical, 5 were graft-related, 7 were plating-related, and 7 were medical. Solid bony fusion was achieved in 65 (92.9%) of the 70 surviving patients. The mean follow-up time was 23.4 months. An overall favourable outcome was achieved in 88% of cases.Conclusion. The outcomes in this series indicate that cervical corpectomy is an effective method for treating traumatic lesions, degenerative disease, tumours and infectious processes involving the anterior and middle portions of the cervical spine.

Lumbar Disc Herniation in Adolescence

Lumbar disc herniation very rarely occurs in adolescence. The aim of this study was to assess the radiological, clinical and surgical features and case outcomes for adolescents with lumbar disc herniation, and to compare with adult cases. The cases of 17 adolescents (7 girls and 10 boys, age range 13–17 years) who were surgically treated for lumbar disc herniation in our clinic between 1998 and 2003 were retrospectively reviewed. The mean follow-up time for these cases was 60 months. The collected histories revealed that 14 (82%) of the 17 cases involved trauma or intense sports activity. Low back pain was the most common complaint (15 cases, 88%). None of the 17 patients had major symptoms during follow-up, and most were engaged in intense sports or heavy work-related activities during this period. The main features of lumbar disc herniation in adolescents are different from those seen in adults. Careful assessment is vital to avoid misdiagnosis and prevent undesirable results from inappropriate surgery. When surgery is indicated and patients are carefully selected, the results of lumbar discectomy in adolescence can be satisfactory.

Superficial siderosis due to papillary glioneuronal tumor

Superficial siderosis of the central nervous system is a rare, progressive, irreversible and debilitating neurological disease characterized by the deposition of haemosiderin in the leptomeninges and the subpial layers of the brain and spinal cord. The main clinical findings are progressive bilateral sensorineural hearing loss, cerebellar ataxia and pyramidal tract signs. The present report describes a 49-year-old woman who presented with intermittent headache of 5 years duration. The pain had become more severe in the previous 6 months. Neurological examination revealed nothing abnormal. Computed tomography showed a cystic mass with apparent internal haemorrhage in the right frontal lobe and T(2)-weighted magnetic resonance imaging showed material of low signal intensity coating the entire surface of the brain. The mass was completely excised via craniotomy. A histopathological study identified the mass as a papillary glioneuronal tumour. The patient recovered well and is still neurologically normal 1 year later. This is the first documented case of superficial siderosis caused by this type of tumour.

Surgical treatment of intramedullary spinal cord ependymomas: Can outcome be predicted by tumor parameters?

Objective: The aim of this study was to investigate whether the tumor parameters of spinal intramedullary ependymomas are significant predictors of clinical presentation and postsurgical outcome. Methods: The study involved 21 cases of intramedullary ependymoma that were operated on between 1988 and 2001. The patients were 13 males (62%) and 8 females (38%), with an age range of 9-70 years (median 38 years). Results: In most cases (13; 62%), preoperative neurologic examination revealed a sensorimotor deficit in at least one limb. Complete tumor removal was achieved in all cases. The patients with wider tumors had poorer preoperative neurologic condition and poorer neurologic outcome. Tumor length (equivalent to myelotomy length) was not correlated with preoperative neurologic status, but longer length was significantly associated with development of dysesthesia post surgery. In contrast to tumor length, tumor/cord ratio (ratio of the tumor width to the largest cord width at the tumor site) was identified as a significant predictor of preoperative neurologic status and outcome. Ratio values of >0.80 were correlated with poorer preoperative clinical status and poorer neurologic outcome. Neither extent of edema (determined from length [in millimeters] of hyperintensity on T2-weighted images) nor presence of a cyst in the tumor was significant relative to postoperative neurologic recovery in these cases. Conclusions: This study demonstrated that the width of the tumor relative to the cord is the main predictor of neurologic presentation and postoperative status. The length of the tumor affects the postoperative dysesthesia development.

The effects of inflammatory response associated with traumatic spinal cord injury in cutaneous wound healing and on expression of transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factor (PDGF)-A at the wound site in rats

At the cellular level, spinal cord injury (SCI) provokes an inflammatory response that generates substantial secondary damage within the cord, but also may contribute to its repair. The aim of this study was to investigate the effects of inflammatory response associated with SCI in cutaneous wound healing and on expression of transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factor (PDGF)-A at the wound site in rats. At the 14th day analysis, the mean TGF-β1 score in trauma group (I) was significantly lower than that in control group (C) (2.60 ± 0.90 vs. 3.64 ± 0.37, respectively; p < 0.05). The mean score for PDGF-A expression in group I was similar to the corresponding value in group C (2.42 ± 0.74 vs. 2.94 ± 0.72, respectively). Compared to group C, group I had significantly lower mean scores for epidermal and dermal regeneration, but higher mean scores for granulation tissue thickness and similar scores for angiogenesis. The dermal layer contains diffuse deposition of collagen fibers that are not organised as in control rat skin, and intraepidermal and subepidermal vasocongestion is distinct. Based on the results on the parameters evaluated in the study, experimental SCI in rats results in delay in wound healing and low intensity of TGF-β1 in the dorsal wound-tissue specimens.

Effects of parenteral fish-oil emulsion (Omegaven) on cutaneous wound healing in rats treated with dexamethasone

BACKGROUND The aim was to assess wound healing when parenteral fish-oil emulsion is given to rats receiving dexamethasone. METHODS For 5 days after skin wounding, group S (control; n = 7) received saline 1 mL/kg intraperitoneal (IP); group D (n = 7), dexamethasone 0.2 mg/kg IP; and group DO (n = 9), dexamethasone 0.2 mg/kg IP plus 1 mL/kg Omegaven (Fresenius Kabi, Austria). Wound specimens were assessed for hydroxyproline level, wound depth, histology (epidermal/dermal regeneration, granulation tissue thickness, and angiogenesis), and expression of transforming growth factor-beta (TGF-beta) and platelet-derived growth factor-AA (PDGF-AA). RESULTS Compared with D and DO specimens, controls had higher hydroxyproline (p < .01), deeper wounds (p < .05), and better histologic scores (p < .01 angiogenesis; others p < .05). There were no significant differences between the group D and DO means for hydroxyproline level, wound depth, or histologic scores (p > .05 for all). Controls had higher TGF-beta expression scores than the other groups (p < .01 for both) and a higher PDGF-AA expression score than group DO (p < .01). Groups D and DO had statistically similar TGF-beta scores, but group D had a higher PDGF-AA score (2.71 +/- 0.75 vs 1.55 +/- 0.72, respectively; p < .05). CONCLUSIONS According to the parameters we studied, adding parenteral omega-3 and omega-6 fatty acids to the nutrition regimen of rats treated with dexamethasone does not seem to have adverse effects on wound healing, and effects on wound healing may not need to be considered when determining if these agents should be supplemented in nutrition support regimens.

Biomechanical comparison of inside-outside screws, cables, and regular screws, using a sawbone model

Our aim was to conduct a biomechanical comparison of the pull-out strengths of inside–outside (I/O) screws, cables, and bone screws to determine whether I/O screws provide greater pull-out resistance than cables or bone screws, and their effectiveness with the screw diameter. There is no remarkable biomechanical experimental study comparing the I/O technique with conventional spinal techniques. The diameter of the screw heads were also biomechanically tested to determine the optimal size that can be used. In this study, 45 blocks of 50×50×5 mm of “sawbone” (synthetic bone, model 1137, Pacific Research Laboratories, Vashon, WA, USA) were used as bone substitutes. Fifteen sets of 14-mm inside–outside Dynalok screws and nuts, 15 wire cables, and 15 bone screws were inserted into a separate sawbone block. An MTS Bionx materials testing machine was used to measure the load to failure of each implant. The mean values and standard deviations of each group were calculated and Student’s t-test was used for comparison. The load to failure of the inside–outside screws was significantly greater than that of the cables (p<0.0000004) and the regular bone screws (p<0.000002). The results also revealed that increasing the diameter of the head of the screw also increases the resistance against the pull-out strengths. Thus, using a larger screw in occipitocervical stabilization provides safe and stable fixation of the occipital bone to the cervical spine. This study also proved that sawbone is a useful and reliable alternative to allogenic fresh cadaveric bone grafts or animal bones for certain biomechanical testing.

Moyamoya disease and anesthesia

Moyamoya disease is a condition that results from bilateral stenosis or obstruction of the intracranial arteries at the base of the brain. Patients exhibit ischemic symptoms, and vascular reconstruction is the therapy of choice. Surgical treatment for Moyamoya disease is often complicated by cerebral ischemia, so the goal in perioperative management is to maintain the balance between oxygen supply and demand in the brain. This report presents three cases of Moyamoya disease in patients under 3 years of age, and discusses anesthesia management issues for pediatric patients with this condition.